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TT: Tiefe Temperaturen
TT 13: Transporteigenschaften und kritische Ströme in HTSL
TT 13.6: Talk
Tuesday, March 27, 2001, 18:15–18:30, J
Angle Dependence of the Thermal Hall Effect in Y123 Crystals — •Roberto Ocaña and Pablo Esquinazi — Abt. Supraleitung und Magnetismus, Institut für Experimentelle Physik II, Universität Leipzig, D-04103 Leipzig
We present results of the thermal Hall conductivity κxy of twinned and untwinned single crystals of optimally doped Y123 HTSC, at different angles θ between the magnetic field B, applied parallel to the CuO2 planes, and the heat current direction. For the first time, a twofold variation in the field-angle dependence, i.e. κxy=κxy0 sin(2θ), was clearly observed in both crystals at ∼ 10 K ≤ T ≤ 70 K, as it was suggested in previous experimental and theoretical work. We found that κxy0(T,B) = a(T) B ln(1/b(T)B) where a and b are temperature and sample dependent parameters. This dependence agrees with the scenario in which the change in quasiparticle occupation number is due to the Doppler shift in the presence of vortex-supercurrents [1]. On the other hand, the temperature dependence of κxy0 shows a maximum at ∼ 30 K which appears to be related with the collapse of the inelastic scattering rate below Tc and the decrease of the number of quasiparticles with decreasing temperature as in the case of the longitudinal conductivity.
[1] H. Won and K. Maki, cond-mat/0004105.